<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div class="root">
       <div class="inner"></div>
    </div>
</body>
<script>
    document.querySelector('.root').addEventListener('click',()=>{
        console.log('root点击了');
    },true)
    document.querySelector('.inner').addEventListener('click',()=>{
        console.log('inner点击了');
    })
</script>
<style>
  .root{
    width: 200px;
    height: 200px;
    background-color: red;
  }
  .inner{
    width: 100px;
    height: 100px;
    background-color: greenyellow;
  }
</style>
</html>